More than 390 000 children are newly infected with HIV each year, only 28 per cent of whom benefit from early infant diagnosis (EID). Rwanda's Ministry of Health identified several major challenges hindering EID scale-up in care of HIV-positive infants. It found poor counseling and follow-up by caregivers of HIV-exposed infants, lack of coordination with maternal and child health-care programs, and long delays between the collection of samples and return of results to the health facility and caregiver. By increasing geographic access, integrating EID with vaccination programs, and investing in a robust mobile phone reporting system, Rwanda increased population coverage of EID from approximately 28 to 72.4 per cent (and to 90.3 per cent within the prevention of mother to child transmission program) between 2008 and 2011. Turnaround time from sample collection to receipt of results at the originating health facility was reduced from 144 to 20 days. Rwanda rapidly scaled up and improved its EID program, but challenges persist for linking infected infants to care.Journal of Public Health Policy advance online publication, 29 November 2012; doi:10.1057/jphp.2012.62.